A fuel stack is normally constituted as a stacked body for which are stacked a plurality of single cells which contain a power generating element, which contains electrocatalytic layers arranged on both surfaces of the electrolytic membrane and electrolytic membrane, as well as a separator. With this fuel cell stack, at both ends of the stacked body are stacked in order a collector plate, an insulation plate, and an end plate, and the stacked state is maintained by fastening the pair of end plates using a fastener member. The end plates do not emit heat because they do not generate power, and also a large portion is in contact with air, so the heat dissipates even during operation of the fuel cell, so cooling occurs naturally. Because of that, a number of single cells positioned at the end part of the stacked body are cooled by heat conduction, and there was the problem that flooding occurred.
For this kind of problem, technology that smoothes the temperature distribution of the fuel cell stack using a heater during operation of the fuel cell stack has been proposed (see Patent Reference 1, for example).